The ability of our nervous system to represent the sensory environment requires a hierarchy of processing from the peripheral sensory receptors to sensory association areas in the cortex. While the overall structure of this hierarchy of the somatosensory system has been well-described, how information is represented at each level is not as well understood. Therefore, the goal of this proposal is to reveal how information from the peripheral somatosensory system is integrated into the representation at the primary somatosensory cortex. We will use two-photon calcium imaging and in vivo electrophysiology with carefully applied mechanical stimulation to elucidate the spatial organization of mouse somatosensory cortical neurons with defined tuning properties. In particular, we will focus on how information is represented with single-cell resolution within cortical layers and how information is represented and transformed at different levels of the cortical hierarchy. Selective activation and silencing of peripheral mechanoreceptors will be used to determine the sufficiency and necessity of subtypes of mechanoreceptors for the production of tuning properties within neurons of primary somatosensory cortex. These experiments will enhance our conceptual understanding of information processing in sensory cortices, potentially leading to enhanced design of brain-machine interfaces.